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    <script>
        // 实现一个函数createCounter，接受一个初始值作为参数，返回一个新的函数，每次调用该函数返回一个递增的数字，初始值为createCounter函数的参数，但是当调用该函数时传入一个参数，会将计数器的值重置为传入的参数
        const createCounter = a => {
            
            const counter = (b) => {
                a++
                if(b != null) {
                    a = b
                    a++
                }
                return a
            }
            return counter
        }


        //实现以下效果
        const counter = createCounter(5);
        console.log(counter()); // 6
        console.log(counter()); // 7
        console.log(counter()); // 8
        console.log(counter(10)); // 11
        console.log(counter()); // 12
    </script>
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